Generally, window materials of synthetic resins are prepared by extruding profiles, whose surfaces are almost color coated with white paints. Therefore, when windows are prepared from these materials and installed in buildings, the white exterior structures are displayed. Since these window materials have a single color, persons have generally feelings weaker than those of windows prepared by metal materials, when they view buildings outside. Therefore, aesthetic properties may be scarce, including surface texture and brightness. In addition, since paints have long curing times, curing works take much time and thus mass productivity is restricted.
Recently, when surfaces of three-dimensional products are applied, spray coating methods are mainly used. In addition, when surfaces of two-dimensional products are applied, roll coating methods are mainly used. However, no coating apparatus and coating method has been proposed, providing a metallic texture with surfaces of window materials by simultaneously using a spray coating method and a roll coating method.